If the pressure on an ideal gas is increased, the volume of the gas will decrease. This can be predicted with the use of the ideal gas equation which is expressed as: PV = nRT. At constant temperature, we can say that pressure and volume are inversely related. Thus, as one value increase, the other decrease.
when you strongly heat the potassium chlorate it leaves oxygen if you'll not heat it strongly to decompose it the oxygen would not release and the compound will remain thermally unstable.
